It is known to control the injection of fuel for internal combustion engines in dependence upon the particular elevation at which the engine operates. According to the actual operating elevation above standard zero, a so-called elevation correction is undertaken to adapt the particular quantity of fuel fed to the engine for maintaining preset mixture components of the air/fuel mixture with decreasing air density. In this way, it is prevented that an increasingly rich mixture is fed to the engine in a motor vehicle which moves between various elevations, for example, starting at sea level and driving into the mountains. An increasingly rich mixture not only increases fuel consumption, it also effects a reduction in power.
In fuel-injection apparatus, various load sensors are provided for detecting the actual air mass supplied to the engine. The load signal issued by the load sensor is usually combined with further operating-characterizing parameters from which the duration of injection or the injected quantity for the fuel injection is determined. An elevation-dependent reduction of the injected fuel can be provided to prevent the fuel mixture from becoming overrich. To achieve this, it is known to provide an altimeter in motor vehicles and to correct the injected quantity of fuel or the ignition angle in dependence upon its measurement signal. Such an elevation correction requires an additional elevation sensor and therefore involves increased cost.